As a Shadowhunter if you get grabbed it will reduce your demon forge gauge to 0 deform you and wipe your current stats off the mvp board. After doing this on purpose a couple times with friends we got a mvp screen to say 26% damage dealt at #1 then 2-4 where all blank as I did all the damage as shadowhunter minus 26% and other 2 were afk. Not sure why getting grabbed by deskulta just erases everything including your guage but it does randomly.
Hmm, strange .
What is your character name and your server? Thank you for giving information on how to reproduce this though.